/* Lesson page */

/* Header, intro and grammar grid */
.lesson-head {
  position: relative;
  padding-left: 26px;
  margin-bottom: 22px;
}
/* the yellow bar beside the title grows down when the lesson opens */
.lesson-head::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 8px;
  border-radius: 2px;
  background: var(--signal);
  transform-origin: 50% 0;
  transition: transform 0.9s var(--ease-out);
}
.lesson-head.pre-draw::before {
  transform: scaleY(0);
}
.lesson-head h1 {
  margin-bottom: 4px;
  overflow-wrap: break-word;
  -webkit-hyphens: auto;
  hyphens: auto;
}
.lesson-head .en {
  font: 600 22px/1.2 var(--cond);
  color: var(--muted);
}
.intro {
  font-size: 18px;
}
.lesson-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 18px;
  margin: 26px 0 18px;
  align-items: start;
}
@media (max-width: 820px) {
  .lesson-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* Rules and spoken examples */
ul.rules {
  padding-left: 20px;
  margin: 0;
}
ul.rules li {
  margin-bottom: 8px;
  max-width: 62ch;
}
.ex-list {
  display: grid;
  gap: 14px 24px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
@media (max-width: 700px) {
  .ex-list {
    grid-template-columns: minmax(0, 1fr);
  }
}
.say {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}
.de-line {
  font-weight: 600;
}
.en-line {
  font-size: 15px;
  color: var(--muted);
}

/* Exercises section and progress bar */
.exercises {
  padding: 36px 0 20px;
}
.lprog {
  position: sticky;
  top: calc(env(safe-area-inset-top, 0px) + var(--nav-h));
  z-index: var(--z-sticky);
  background: var(--bg);
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 0;
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 10px;
}
.lprog .bar {
  flex: 1;
  height: 6px;
  background: var(--line);
  border-radius: 3px;
  overflow: hidden;
}
.lprog .bar i {
  display: block;
  height: 100%;
  width: 0;
  background: var(--ok);
  transition: width 0.4s;
}

/* Words and pager */
.vocab {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 8px;
}
.vocab div {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  font-size: 16px;
  transition:
    border-color 0.2s,
    box-shadow 0.3s var(--ease-out),
    translate 0.3s var(--ease-out);
}
.vocab div:hover {
  border-color: color-mix(in srgb, var(--text) 16%, var(--line));
  box-shadow: var(--shadow-1);
  translate: 0 -1px;
}
.vocab div > span:last-child {
  color: var(--muted);
  text-align: right;
}
.vocab .pl {
  display: block;
  font-size: 13px;
  color: var(--muted);
}
.pager {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin: 30px 0 52px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .lprog .bar i {
    transition: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .lesson-head::before {
    transition: none;
  }
}